Chemical potential fluctuations in topological insulator (Bi0.5Sb0.5)2Te3-films visualized by photocurrent spectroscopy. (27th May 2015)

• Record Type: Journal Article
• Authors: Kastl, Christoph; Seifert, Paul; He, Xiaoyue; Wu, Kehui; Li, Yongqing; Holleitner, Alexander
• Is Part Of: 2D materials. Volume 2:Number 2(2015)
• Publication Date: 2015-05-27
• Subjects: topological insulator -- surface state -- nanoscale optoelectronics -- photo-thermoelectric current -- atomic force microscope lithography -- nanofabrication -- dynamic plowing lithography; Graphene -- Periodicals; Materials science -- Periodicals; Nanostructured materials -- Periodicals; 620.115
• DOI: 10.1088/2053-1583/2/2/024012
• Languages: English
• ISSNs: 2053-1583

Abstract

Abstract: We investigate the photocurrent properties of the topological insulator (Bi0.5 Sb0.5 )2 Te3 on SrTiO3 -substrates. We find reproducible, submicron photocurrent patterns generated by long-range chemical potential fluctuations, occurring predominantly at the topological insulator/substrate interface. We fabricate nano-plowed constrictions which comprise single potential fluctuations. Hereby, we can quantify the magnitude of the disorder potential to be in the meV range. The results further suggest a dominating photo-thermoelectric current generated in the surface states in such nanoscale constrictions.